Table 4.
Multivariate results for the outcome of major amputation
| Variable | Odds ratio | 95% CI | P value |
|---|---|---|---|
| Age | |||
| Q1: 21–61 years | Reference | ||
| Q2: 62–70 years | 0.759 | 0.720, 0.800 | <.0001 |
| Q3: 71–78 years | 0.818 | 0.770, 0.869 | <.0001 |
| Q4: ≥ 79 years | 1.192 | 1.117, 1.272 | <.0001 |
| Race: | |||
| White | Reference | ||
| Black | 2.149 | 1.994, 2.316 | <.0001 |
| Hispanic | 1.600 | 1.464, 1.749 | 0.0814 |
| Asian/Pacific Islander | 1.302 | 1.079, 1.571 | 0.1197 |
| Native American | 2.002 | 1.519, 2.640 | 0.0107 |
| Other | 1.166 | 0.996, 1.364 | 0.0009 |
| Gender: | |||
| Male | Reference | ||
| Female | 0.798 | 0.771, 0.826 | <.0001 |
| Median income by zip code: | |||
| Q1 | 1.342 | 1.240, 1.453 | <.0001 |
| Q2 | 1.257 | 1.166, 1.356 | 0.0002 |
| Q3 | 1.115 | 1.037, 1.199 | 0.0145 |
| Q4 | Reference | ||
| Primary payer: | |||
| Medicare | Reference | ||
| Private insurance | 0.738 | 0.696, 0.783 | <.0001 |
| Medicaid | 1.257 | 1.171, 1.349 | <.0001 |
| Uninsured | 1.052 | 0.923, 1.199 | 0.4477 |
| Co-morbidity: | |||
| Congestive heart failure | 3.281 | 3.081, 3.495 | <.0001 |
| Vavular disease | 1.348 | 1.235, 1.472 | <.0001 |
| Pulmonary circulation disorders | 1.293 | 1.098, 1.522 | 0.0020 |
| Peripheral vascular disorders | 0.400 | 0.377, 0.425 | <.0001 |
| Hypertension | 0.771 | 0.739, 0.803 | <.0001 |
| Paralysis | 2.775 | 2.525, 3.049 | <.0001 |
| Neurological disorders | 2.178 | 2.031, 2.335 | <.0001 |
| Chronic pulmonary disease | 0.735 | 0.704, 0.768 | <.0001 |
| Diabetes mellitus, uncomplicated | 0.802 | 0.763, 0.842 | <.0001 |
| Diabetes mellitus with chronic complications | 2.167 | 2.050, 2.290 | <.0001 |
| Hypothyroidism | 0.930 | 0.872, 0.992 | 0.0285 |
| Renal failure | 1.194 | 1.138, 1.253 | <.0001 |
| Liver disease | 1.319 | 1.149, 1.513 | <.0001 |
| Metastatic cancer | 1.433 | 1.153, 1.779 | 0.0012 |
| Coagulopathy | 1.103 | 1.001, 1.215 | 0.0471 |
| Obesity | 0.808 | 0.747, 0.874 | <.0001 |
| Weight loss | 2.570 | 2.336, 2.827 | <.0001 |
| Fluid and electrolyte disorders | 1.642 | 1.568, 1.720 | <.0001 |
| Chronic blood loss anemia | 1.696 | 1.623, 1.772 | <.0001 |
| Deficiency anemias | 1.696 | 1.623, 1.772 | <.0001 |
| Drug abuse | 1.253 | 1.030, 1.524 | 0.0238 |
| Psychoses | 1.848 | 1.650, 2.070 | <.0001 |
| Depression | 1.653 | 1.536, 1.779 | <.0001 |
| Diagnostic angiogram | 0.094 | 0.088, 0.101 | <.0001 |
| Admission status: | |||
| Elective | Reference | ||
| Non-elective | 2.192 | 2.060, 2.333 | <.0001 |
| LER volume: | |||
| Q1: 0–11/year | 15.163 | 12.497, 18.397 | <.0001 |
| Q2: 12–71/year | 2.752 | 2.439, 3.105 | <.0001 |
| Q3: 72–248/year | 1.767 | 1.609, 1.940 | <.0001 |
| Q4: ≥ 249/year | Reference | ||
| Hospital teaching status: | |||
| Teaching | 1.132 | 1.021, 1.254 | 0.0186 |
| Non-teaching | Reference | ||
| Geographic region: | |||
| Northeast | 0.769 | 0.675, 0.875 | 0.0287 |
| Midwest | 0.807 | 0.704, 0.925 | 0.3041 |
| South | Reference | ||
| West | 0.831 | 0.737, 0.937 | 0.6399 |
| Model C statistic 0.865, R-square 0.8983 | |||